diff --git a/Heap/heap.h b/Heap/heap.h
index 7e7b395ace32b84937ef4bb37921e8371fac7cb7..ce1e01a832bd15d31b7791ea7a93491ad7d95229 100644
--- a/Heap/heap.h
+++ b/Heap/heap.h
@@ -1,3 +1,5 @@
+#ifndef _HEAP_H_
+#define _HEAP_H_
 #include <stdio.h>
 
 #define MAX_ELEMENT 200
@@ -16,3 +18,5 @@ void init(HeapType* pH);
 element delete_max_heap(HeapType *pH);
 
 void insert_max_heap(HeapType* h, element item);
+
+#endif